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Page 1: A STAINING METHOD FOR THE DIRECT TYPING OF PNEUMOCOCCI

22 CLINICAL AND LABORATORY NOTES

fixation. This is serological evidence supportingRamsay Hunt’s clinical explanation of such cases asdue to specific zoster infection of the geniculateganglion.

2. The sera of 22 cases of Bell’s palsy without zoster-like eruptions have been found to contain zosterantibodies in only four instances. Our evidence thussuggests that the majority of such cases are not dueto an infection with zoster virus.

We wish to acknowledge with gratitude a greatdeal of help and advice given us by Dr. S. P. Bedson,of the Freedom Research Laboratory in the LondonHospital. One of us (R. T. B.) was assisted by agrant from the Yarrow Research Funds.

REFERENCES

1. Hunt, R. : Jour. Nerv. and Ment. Dis., 1907, xxxiv., 73.2. Antoni (quoted by Key-Aberg) : Acta Oto-laryng., 1928,

xii., 372.3. Kundratitz, K. : Zeit. f. Kinderheilk, 1925.4. Bruusgaard, E. : Brit. Jour. Dermat. and Syph., 1932,

xliv., 1.5. Netter, A., and Urbain, A. : Compt. rend. Soc. de biol.,

1924, xc., 189, 461, 997.6. Lauda, A., and Silberstern, E. : Klin. Woch., 1925, iv., 1871.7. Bedson, S. P., and Bland, J. O. W. : Brit. Jour. Exp. Path.,

1929, x., 393.

Clinical and Laboratory NotesA STAINING METHOD FOR THE DIRECT

TYPING OF PNEUMOCOCCI

BY F. C. O. VALENTINE, M.B. CAMB.,M.R.C.P. LOND.

ASSISTANT DIRECTOR OF THE HALE CLINICAL LABORATORIES.LONDON HOSPITAL

AN important advance in the serum treatmentof lobar pneumonia was made when Armstrong 1 2and Logan and Smeall3 in simultaneous papersshowed that the direct typing of pneumococci in

sputum was possible. However it is not always easy,at least for the unpractised eye, to recognise theunstained swollen capsules on which their methoddepends.The object of the present communication is to

point out that the " neutralised " capsule can bestained by ordinary dyes. The following techniqueis simple and reasonably quick.

Three or four loopfuls of Type I. serum are mixed on aslide with a fair-sized loopful of sputum and mounted witha cover-glass. The edges of the cover-glass are sealedwith vaseline, so that it will not become stuck to the slide.Similar preparations are made with Types II. and III. sera.It is essential that complete neutralisation of the capsuleshould be obtained, and to ensure this the preparationsshould be left for 20 to 30 minutes. After this the cover-slips are slid off and discarded. The films left on the slidesare allowed to dry and the bulk of the vaseline is scrapedoff with a knife. The vaseline remaining will not interferewith the staining and blotting of the slides, and it mayfinally be removed by warming until it is just melted andwashing over with xylol. Before staining wash the filmunder the tap to remove the serum, stain for 2 to 3 minuteswith dilute carbol fuchsin, wash and counter-stain for10 seconds with carbol thionin ; wash and blot dry.

It will be found that the bodies of all bacteria stainpractically black, and that everything else is red.The capsules of pneumococci treated with the homo-logous serum appear quite large and stain a strong red,whereas the " unneutralised " capsule does not stain.The dilute carbol fuchsin used has been filtered Ziehl-

Neelsen stain freshly diluted in a test-tube with five or sixparts of water. The carbol thionin contains nine parts5 per cent. phenol in water and one part 50 per cent. alcoholsaturated with thionin. In a new bottle this stain usuallyprecipitates, but once the bottle is lined with deposit it

lasts well. Saffranin may be used in place of carbol fuchsin,but the capsules are then less intensely stained. Tap-watermay be used for washing slides throughout.

Similar methods are very successful in typing thepneumococci in pus, but in this case a few coccimay be seen with lightly stained capsules in mixtureswith the heterologous sera. This is probably dueto the fact that the patient has had time to producesome antibodies, but it does not appear likely tocause confusion.When pneumococci cannot be found in sputum

and mouse inoculation is inconvenient, a serum agarslope may be inoculated with a good loopful ofsputum and the culture washed off in a little salinenext day. The presence of a few pneumococci maybe gauged by making a film from a loopful of thesuspension mixed with a loopful of normal serum,and staining with carbol thionin or other stain capableof fixing the serum. Capsules will show as an

unstained halo round the cocci. Unstained zones

can, of course, occur in such a film round otherbacteria owing to retraction, but a very littleexperience will enable the pneumococci to beidentified. If they are present, equal volumes of

suspension and of the type sera may be mixed andsealed in capillary pipettes. Films are made afterabout 15 minutes, washed and stained as for sputum.Capsules from cultures are considerably narrowerthan those from sputum or pus but are quiterecognisable. It must, of course, be recognised thatsuch a method is inferior to mouse inoculation, bothin disclosing the presence of very small numbers ofcocci and also in providing no test of virulence.Where large numbers of pneumococci are present,

as in pure cultures or in the peritoneal exudate ofmice, it is only necessary to spread films of theorganisms in loopfuls of the type sera and stain withcarbol thionin. With homologous serum massive

agglutination takes place, usually visible to the nakedeye.

Capsular staining, although unmistakably presentin the agglutinated cocci, is usually less strikingthan in sputum owing to incomplete " neutralisation

"

and insufficient antibody, but the agglutination alonewill readily identify the type. This latter reactionhas been previously described by Sabin,4 who obtainedno capsule staining.

REFERENCES

1. Armstrong, R. R. : Brit. Med. Jour., 1931, i., 214.2. Armstrong, R. R. : Ibid., 1932, i., 187.3. Logan, W. R., and Smeall, J. T. : Ibid., p. 188.4. Sabin, A. B. : Jour. Infect. Dis., 1930, xlvi., 469.

MYELOID LEUKÆMIA TREATED WITH

THE FOUR-GRAMME RADIUM BOMB

BY G. WHITE PHILLIPS, M.B. LIVERP., D.M.R.E.,L.D.S.

RESIDENT MEDICAL OFFICER, WESTMINSTER HOSPITAL ANNEXE

THE treatment of leukaemia by radiation is now

firmly established. No case is cured ; it is open to

question whether life is prolonged at all. Thesuperiority of radiotherapy over all other forms oftreatment is that it can produce in these patientsa temporary return to apparent health.The cause of this condition is unknown, although

several theories of its origin have been advancedfrom time to time. At the moment the balance of

opinion seems to be divided between an inflammatorycondition of the hoemopoietic system and a neoplasticone. Very little is known of the way in which X rays

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